WONT START..

I did the timing on it after the last belt fell off while I was going down the highway. I got the new belt on and the timing done real well, but now I am not getting compression on the back head. My compression is good on the front one just not the rear. Any clues?

Jack thanks for the assistance, the problem actually turned out to be a dowel pin jammed into the cam. Machine shop is gonna fix me right up. What was throwing me off was the whole cylinder head not getting compression, and I was aware how hard those Mazda valves are to bend. Thanks buddy.